Redis入門

一、安裝

目前，官方最新穩定版本為3.0.7

# wget http://download.redis.io/releases/redis-3.0.7.tar.gz

# cd /usr/local/

# tar xvf /root/redis-3.0.7.tar.gz

# cd redis-3.0.7/

# make

二、啟動

安裝完成後，在src目錄下會生成啟動執行程式，包括redis-server,redis-sentinel, redis-benchmark,redis-cli等

# src/redis-server 

該啟動方式是前臺啟動，如果關閉當前終端，則redis會自動關閉

正如登錄信息開頭Warning所顯示的，這種方式啟動沒有使用配置文件，所以並不推薦。預設監聽6379埠

24649:C 03 Feb 16:32:30.242 # Warning: no config file specified, using the default config. In order to specify a config file use src/redis-server /path/to/redis.conf
24649:M 03 Feb 16:32:30.243 * Increased maximum number of open files to 10032 (it was originally set to 1024).
                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 3.0.7 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                   
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 6379
 |    `-._   `._    /     _.-'    |     PID: 24649
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           http://redis.io        
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'                                               

24649:M 03 Feb 16:32:30.246 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
24649:M 03 Feb 16:32:30.246 # Server started, Redis version 3.0.7
24649:M 03 Feb 16:32:30.246 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
24649:M 03 Feb 16:32:30.246 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
24649:M 03 Feb 16:32:30.247 * The server is now ready to accept connections on port 6379

關於redis-server的更多用法，可通過redis-server -h查看

# src/redis-server -h

Usage: ./redis-server [/path/to/redis.conf] [options]
       ./redis-server - (read config from stdin)
       ./redis-server -v or --version
       ./redis-server -h or --help
       ./redis-server --test-memory <megabytes>

Examples:
       ./redis-server (run the server with default conf)
       ./redis-server /etc/redis/6379.conf
       ./redis-server --port 7777
       ./redis-server --port 7777 --slaveof 127.0.0.1 8888
       ./redis-server /etc/myredis.conf --loglevel verbose

Sentinel mode:
       ./redis-server /etc/sentinel.conf --sentinel

配置文件中常用參數如下：

daemonize:是否以後臺daemon方式運行，預設是前臺方式運行，即預設值為no

pidfile:pid文件位置，預設為:/run/redis.pid

port:監聽的埠號，預設為6379

bind 127.0.0.1 配置監聽網卡的ip，針對有多個網卡的場景

logfile:log文件位置，預設值為stdout，使用“標準輸出”，預設後臺模式會輸出到/dev/null

loglevel notice ，指定日誌記錄級別，Redis總共支持四個級別：debug,verbose,notice,warning，預設為notice

     Debug:記錄很多信息，用於開發和測試

     Verbose:很多精簡的有用信息，不像debug會記錄那麼多

     Notice:普通的verbose，常用於生產環境

     Warning:只有非常重要或者嚴重的信息會記錄到日誌

三、設置開機自啟動

 將啟動腳本複製到/etc/init.d目錄下

# cp /usr/local/redis-3.0.7/utils/redis_init_script /etc/init.d/redisd

編輯啟動腳本

# vim /etc/init.d/redisd

#!/bin/sh
# chkconfig:2345 90 10
# Simple Redis init.d script conceived to work on Linux systems
# as it does use of the /proc filesystem.

REDISPORT=6379
EXEC=/usr/local/redis-3.0.7/src/redis-server
#EXEC=/usr/local/bin/redis-server
CLIEXEC=/usr/local/redis-3.0.7/src/redis-cli

PIDFILE=/var/run/redis_${REDISPORT}.pid
CONF="/etc/redis/${REDISPORT}.conf"

主要做了兩項修改，

一、添加了# chkconfig:2345 90 10

二、指定了redis-server和redis-cli的位置

EXEC=/usr/local/redis-3.0.7/src/redis-server

CLIEXEC=/usr/local/redis-3.0.7/src/redis-cli

註意：

PIDFILE=/var/run/redis_${REDISPORT}.pid指定了pid文件的位置

CONF="/etc/redis/${REDISPORT}.conf"指定了配置文件的位置

創建配置文件

# cd /etc/

# mkdir redis

# cp /usr/local/redis-3.0.7/redis.conf redis/6379.conf

修改配置文件

主要是設置redis以後臺進程運行和pid文件的位置

daemonize yes
pidfile /var/run/redis_6379.pid

以服務方式啟動redis

# /etc/init.d/redisd start

Starting Redis server...

# ps -ef |grep redis

root      29836      1  0 18:23 ?        00:00:00 /usr/local/redis-3.0.7/src/redis-server *:6379
root      29846   4110  0 18:23 pts/0    00:00:00 grep --color=auto redis

客戶端連接測試

# cd /usr/local/redis-3.0.7/src/

# ./redis-cli 

127.0.0.1:6379> set 123 hello
OK
127.0.0.1:6379> get 123
"hello"

預設連接到localhost 6379，查看伺服器信息，可通過info命令。